#1 The top plate (grid connection) is 3" square; the hole is 1 and 7/16" diameter.
#2 The PCB (cathode & filament connections) is 2" square; the hole is 5/16" diameter.
#3 The spacing between the top plate and PCB is 1".
#4 The cathode-filament connection is on the top of the PCB.
#5 The grid plate is mounted 5/8 to 7/8" below the chassis, as layout permits. The hole in
the chassis is 2.25" diameter.